The respiratory form of tularemia, a potentially serious bacterial disease, is a significant public health concern because it is highly infectious, it has a high mortality rate if untreated, and it could be introduced into a population in an intentional act of bioterror. Though much research is focused on developing drugs and vaccines targeted to the bacterium that causes tularemia, Francisella tularensis, little is known about the role that antibodies play in protecting against infection.
A research team led by Dennis W. Metzger, Ph.D., at the Albany Medical College in New York has now shown that treating laboratory mice with a serum containing tularemia-specific antibodies protects the mice against F. tularensis, not only if given before exposure to lethal doses of inhalational F. tularensis but also up to 48 hours after exposure. These findings suggest a possible alternative treatment approach to traditional antibiotics. In the absence of a licensed vaccine, such an approach might prove especially useful early on in the case of an intentional act of bioterrorism. The tularemia-specific antibodies may enhance an individual’s immune responses to the bacteria after exposure, in essence acting as a surrogate vaccine. Other advantages of this approach over conventional methods of treatment include the fact that it is rapid and specific; it could be used in people with weakened immune systems; and it minimizes the chances of contributing to treatment-resistant bacteria.